Compressor and air conditioner

ABSTRACT

According to one embodiment, a compressor includes cylinders, a rotating shaft, bearings, discharge valve mechanisms, and mufflers. As to the mufflers, an outer contour of the muffler chamber is defined by each of an end face part which is a face part on one end side of the muffler in an axial direction of the rotating shaft, a brim part which is a face part on the other end side in the axial direction, and a side face part which joins the end face part and the brim part to each other in a cylindrical form in the circumferential direction of the rotating shaft, and one of the mufflers includes a concave part formed by denting each of the end face part and the side face part toward the inside of a muffler chamber.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2021-140934, filed Aug. 31, 2021, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a compressor and air conditioner including the compressor.

BACKGROUND

A refrigerating cycle device such as an air conditioner or the like is equipped with a compressor configured to compress the refrigerant. The compressor includes, as main components, for example, an electric-motor unit configured to rotate, for example, a rotating shaft, compression-mechanism unit coupled to the electric-motor unit through the rotating shaft, and airtight container accommodating therein the electric-motor unit and compression-mechanism unit. The electric-motor unit includes, for example, a so-called inner-rotor type motor and includes a rotor firmly fixed to the rotating shaft and stator fixed to the inner circumferential part of the airtight container. The rotating shaft includes crank parts (eccentric parts). The compression-mechanism unit includes cylinders each forming, for example, cylinder chambers, and rollers fitted onto the eccentric parts of the rotating shaft and eccentrically rotated inside the cylinder chambers. The inside of the cylinder chamber is partitioned into a suction chamber and compression chamber of the refrigerant with a vane. The rotating shaft is rotatably supported with bearings. The bearing includes a flange part defining a surface in the cylinder chamber in the axial direction of the rotating shaft, and boss part extending in a cylindrical form from the flange part. Further, a muffler configured to suppress pulsation and noise caused by the refrigerant to be compressed by the cylinder of the compression-mechanism unit and discharged into the airtight container is attached to the bearing.

The flange part includes a discharge port from which the refrigerant compressed by the cylinder is discharged into the airtight container, and discharge valve mechanism configured to control opening/closing of the discharge port. For this reason, the flange part includes a concave part (dug-down part) in which the discharge valve mechanism is to be installed in the vicinity of the discharge port. The dug-down part is formed by digging down one surface in the bearing in the axial direction of the rotating shaft, for example, the top surface of the flange part to a predetermined depth. Accordingly, the dug-down part has a less thickness as compared with other portions of the flange part, and the rigidity thereof is liable to become relatively lower in the bearing. Accordingly, when the rotating shaft is rotated, there is a possibility of the dug-down part being elastically deformed in such a manner as to incline the boss part toward, for example, the flange part. Depending on the degree of such a deformation of the dug-down part, there is a possibility of the support rigidity of the rotating shaft based on the bearings being lowered, and possibility of the rotating shaft causing bending vibration and enhancing the noise.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a circuit diagram schematically showing the configuration of an air conditioner according to an embodiment.

FIG. 2 is a vertical cross-sectional view of a compressor according to the embodiment.

FIG. 3 is a view schematically showing a bearing (first bearing including a first discharge valve mechanism) including a discharge valve mechanism of the compressor according to the embodiment from above.

FIG. 4 is a view schematically showing the cross section of the bearing (first bearing) at the part indicated by the arrows A3 shown in FIG. 3 .

FIG. 5 is a view schematically showing, from above, the state where a muffler (first muffler) of the compressor according to the embodiment is mounted on the bearing (first bearing).

FIG. 6 is a perspective view schematically showing the muffler (first muffler) of the compressor according to the embodiment.

DETAILED DESCRIPTION

In general, according to one embodiment, a compressor comprises cylinders, a rotating shaft, bearings, at least one of discharge valve mechanisms, and at least one of mufflers. The cylinders compress a refrigerant. A rotating shaft arranges inside the cylinders and includes eccentric parts. Each of the bearings includes a flange part defining a surface in the cylinder in an axial direction of the rotating shaft, and a boss part extending in a cylindrical form concentric with the rotating shaft so as to be continuous with the flange part and rotatably supporting the rotating shaft. At least one of the discharge valve mechanisms is arranged in the flange part and includes a discharge valve deformed to be opened when the refrigerant compressed by the cylinder reaches a predetermined discharge pressure and lengthwise in a predetermined direction, and a valve presser suppressing further deformation of the discharge valve when the discharge valve is opened. At least one of the mufflers covers the bearing so as to surround a part between the flange part and the boss part and forms, between the flange part and the boss part, a muffler chamber into which the refrigerant compressed by the cylinder is discharged. As to the mufflers, an outer contour of the muffler chamber is defined by each of an end face part which is a face part on one end side of the muffler in the axial direction of the rotating shaft, a brim part which is a face part on the other end side in the axial direction of the rotating shaft, and a side face part which joins the end face part and the brim part to each other in a cylindrical form throughout the entire circumference in the circumferential direction of the rotating shaft, and at least one of the mufflers includes a concave part formed by denting each of the end face part and the side face part toward the inside of the muffler chamber.

An embodiment will be described hereinafter with reference to FIGS. 1 to 6 .

FIG. 1 is a refrigerating cycle circuit diagram of an air conditioner 1 according to this embodiment. The air conditioner 1 is a device configured to carry out air conditioning on the basis of such a refrigerating cycle and is an example of the refrigerating cycle device. The air conditioner 1 includes, as main components, a compressor 2, four-way valve 3, outdoor heat exchanger 4, outdoor heat exchanger 4, outdoor air blower 40, expanding device 5, indoor heat exchanger 6, and indoor air blower 60.

As shown in FIG. 1 , the discharge side of the compressor 2 is connected to a first port 3 a of the four-way valve 3. A second port 3 b of the four-way valve 3 is connected to the outdoor heat exchanger 4. The outdoor heat exchanger 4 is connected to the indoor heat exchanger 6 through the expanding device 5. The indoor heat exchanger 6 is connected to a third port 3 c of the four-way valve 3. A fourth port 3 d of the four-way valve 3 is connected to the suction side of the compressor 2 through an accumulator 8.

The refrigerant circulates through a circulation circuit 7 from the discharge side of the compressor 2 to the suction side thereof through the outdoor heat exchanger 4, expanding device 5, indoor heat exchanger 6, and accumulator 8. As the refrigerant, a refrigerant containing no chlorine is desirable and, for example, R448A, R449A, R449B, R407G, R407H, R449C, R456A, R516A, R406B, R463A, R744, and HC-based refrigerant and the like are applicable.

For example, when the air conditioner 1 is operated in the cooling mode, the four-way valve 3 is switched in such a manner that the first port 3 a communicates with the second port 3 b, and third port 3 c communicates with the fourth port 3 d. When the operation of the air conditioner 1 is started in the cooling mode, the high-temperature/high-pressure vapor-phase refrigerant compressed by the compressor 2 is discharged into the circulation circuit 7. The discharged vapor-phase refrigerant is guided to the outdoor heat exchanger 4 functioning as a condenser (radiator) through the four-way valve 3.

The vapor-phase refrigerant guided to the outdoor heat exchanger 4 is condensed by heat exchange with the air (outside air) sucked by the outdoor air blower 40 and is changed into a high-pressure liquid-phase refrigerant. The high-pressure liquid-phase refrigerant is decompressed in the process of passing through the expanding device 5 and is changed into a low-pressure vapor-liquid two-phase refrigerant. The vapor-liquid two-phase refrigerant is guided to the indoor heat exchanger 6 functioning as an evaporator (heat absorber, heat sink) and carries out heat exchange with the air (inside air) sucked by the indoor air blower 60 in the process of passing through the indoor heat exchanger 6.

As a result of this, the vapor-liquid two-phase refrigerant draws heat from the air to thereby evaporate and change into a low-temperature/low-pressure vapor-phase refrigerant. The air passing through the indoor heat exchanger 6 is cooled by the evaporative latent heat of the liquid-phase refrigerant and is sent to the place to be air-conditioned (cooled) by the indoor air blower 60 as a cool wind. The low-temperature/low-pressure vapor-phase refrigerant passing through the indoor heat exchanger 6 is guided to the accumulator 8 through the four-way valve 3. When a liquid-phase refrigerant not fully evaporated is mixed into the refrigerant, the refrigerant is separated into the liquid-phase refrigerant and vapor-phase refrigerant at this place. The low-temperature/low-pressure vapor-phase refrigerant separated from the liquid-phase refrigerant is sucked into the compressor 2 from the accumulator 8 and is compressed again by the compressor 2 into a high-temperature/high-pressure vapor-phase refrigerant and is discharged into the circulation circuit 7. On the other hand, when the air conditioner 1 is operated in the heating mode, the four-way valve 3 is switched in such a manner that the first port 3 a communicates with the third port 3 c, and second port 3 b communicates with the fourth port 3 d. When the operation of the air conditioner 1 is started in the heating mode, the high-temperature/high-pressure vapor-phase refrigerant discharged from the compressor 2 is guided to the indoor heat exchanger 6 through the four-way valve 3 and is made to carry out heat exchange with the air passing through the indoor heat exchanger 6.

In this case, the indoor heat exchanger 6 functions as a condenser.

As a result of this, the vapor-phase refrigerant passing through the indoor heat exchanger 6 condenses by carrying out heat exchange with the air (inside air) sucked by the indoor air blower 60 and changes into a high-pressure liquid-phase refrigerant. The air passing through the indoor heat exchanger 6 is heated by heat exchange with the vapor-phase refrigerant and is sent to the place to be air-conditioned (heated) by the indoor air blower 60 as a warm wind.

The high-temperature liquid-phase refrigerant passing through the indoor heat exchanger 6 is guided to the expanding device 5 and is decompressed in the process of passing through the expanding device 5 and is further changed into a low-pressure vapor-liquid two-phase refrigerant. The vapor-liquid two-phase refrigerant is guided to the outdoor heat exchanger 4 functioning as an evaporator and carries out heat exchange with the air (outside air) sucked by the outdoor air blower 40 to thereby evaporate and change into a low-temperature/low-pressure vapor-phase refrigerant. The low-temperature/low-pressure vapor-phase refrigerant passing through the outdoor heat exchanger 4 is sucked into the compressor 2 through the four-way valve 3 and accumulator 8 and is compressed again by the compressor 2 into a high-temperature/high-pressure vapor-phase refrigerant and is discharged into the circulation circuit 7.

It should be noted that although in this embodiment, the air conditioner 1 is made operable in both the cooling mode and heating mode, the air conditioner 1 may also be a cooling-dedicated device or heating-dedicated device operable in only one of, for example, the cooling mode and heating mode.

Next, the specific configuration of the compressor 2 to be used for the air conditioner 1 will be described below with reference to FIG. 2 . FIG. 2 is a vertical cross-sectional view of the compressor 2. As shown in FIG. 2 , the compressor 2 is a so-called vertical rotary compressor and includes, as main components, an airtight container 10, compression-mechanism unit 11, and electric-motor unit 12. It should be noted that in the following description, on the basis of the relative positional relationship between the compression-mechanism unit 11 and electric-motor unit 12 arranged along the central axis line C1 of the airtight container 10 to be described later, the side on which the compression-mechanism unit 11 is positioned is defined as below, and side on which the electric-motor unit 12 is positioned is defined as above.

The airtight container 10 includes a circumferential wall 10 a having a cylindrical shape and stands vertical relatively to the installation surface. The installation surface is, for example, a bottom plate or the like of the outdoor unit. At the upper end of the airtight container 10, a discharge pipe 10 b is provided. The discharge pipe 10 b is connected to the first port 3 a of the four-way valve 3 through the circulation circuit 7. At the lower part of the airtight container 10, an oil basin part 10 c storing therein the lubricating oil is provided.

The compression-mechanism unit 11 is accommodated in the airtight container 10 at the lower part thereof in such a manner as to be immersed in the lubricating oil. In the example shown in FIG. 2 , the compression-mechanism unit 11 has a twin-type cylinder structure and includes a first cylinder 13, second cylinder 14, and rotating shaft 15 as main components. Each of the first cylinder 13 and second cylinder 14 includes a roller (rolling piston) and vane inside thereof. It should be noted that the number of the cylinders of the compression-mechanism unit is not limited two, and may be one, or greater than or equal to three.

The first cylinder 13 is fixed to the inner circumferential surface of the circumferential wall 10 a of the airtight container 10. The second cylinder 14 is fixed to the undersurface of the first cylinder 13 through a partition plate 18.

To the upper part of the first cylinder 13, a first bearing 20 is fixed. The first bearing 20 covers the bore part of the first cylinder 13 from above and upwardly protrudes from the first cylinder 13. The space surrounded by the bore part of the first cylinder 13, partition plate 18, and first bearing 20 constitutes a first cylinder chamber. The partition plate 18 and first bearing 20 respectively correspond to closure members defining the undersurface of the first cylinder chamber and top surface of the first cylinder chamber.

To the lower part of the second cylinder 14, a second bearing 22 is fixed. The second bearing 22 covers the bore part of the second cylinder 14 from below and downwardly protrudes from the second cylinder 14. The space surrounded by the bore part of the second cylinder 14, partition plate 18, and second bearing 22 constitutes a second cylinder chamber. The partition plate 18 and second bearing 22 respectively correspond to closure members defining the top surface of the second cylinder chamber and undersurface of the second cylinder chamber. The first cylinder chamber and second cylinder chamber are arranged concentrically with the central axis line O1 of the airtight container 10.

The first cylinder chamber and second cylinder chamber are connected to the accumulator 8 through a suction pipe (illustration omitted) serving as a part of the circulation circuit 7. The vapor-phase refrigerant separated from the liquid-phase refrigerant by the accumulator 8 is guided to the first cylinder chamber and second cylinder chamber through the aforementioned suction pipe.

The rotating shaft 15 is positioned in such a manner that the central axis thereof is concentric with the central axis line O1 of the airtight container 10, and penetrates the first cylinder chamber, second cylinder chamber, and partition plate 18. The rotating shaft 15 includes a first journal part 27 a, second journal part 27 b, and a pair of crankpin parts (eccentric parts) 28 a and 28 b. That is, the rotating shaft 15 is configured as a crankshaft. The first journal part 27 a is rotatably supported by the first bearing 20. The second journal part 27 b is rotatably supported by the second bearing 22.

Furthermore, the rotating shaft 15 includes an extension part 27 c concentrically extended from the first journal part 27 a. The extension part 27 c penetrates the first bearing 20 to upwardly protrude from the compression-mechanism unit 11. To the extension part 27 c, a rotor 33 (to be described later) of the electric-motor unit 12 is firmly fixed.

The eccentric parts 28 a and 28 b are positioned between the first journal part 27 a and second journal part 27 b. The eccentric parts 28 a and 28 b respectively have phase differences of, for example, 180° and amounts of eccentricity of the eccentric parts 28 a and 28 b relative to the central axis line O1 of the airtight container 10 are made equal to each other. The eccentric part (hereinafter referred to as a first eccentric part) 28 a on one hand is accommodated in the first cylinder chamber. The eccentric part (hereinafter referred to as a second eccentric part) 28 b on the other hand is accommodated in the second cylinder chamber.

Rollers 16 and 17 are respectively fitted onto the outer circumferential surfaces of the first eccentric part 28 a and second eccentric part 28 b. Between the inner circumferential surface of each of the rollers 16 and 17 and outer circumferential surface of each of the eccentric parts 28 a and 28 b, a small gap allowing each of the rollers 16 and 17 to rotate relatively to each of the eccentric parts 28 a and 28 b is provided. Thereby, when the rotating shaft 15 rotates, each of the rollers 16 and 17 eccentrically rotates inside the cylinder chamber and part of the outer circumferential surface of each of the rollers 16 and 17 comes into contact with the inner circumferential surface of the cylinder chamber through an oil film.

Inside each of the first cylinder 13 and second cylinder 14, a vane (illustration omitted) is arranged. Each of the vanes is supported by each of the cylinders 13 and 14 in a state where each of the vanes is inwardly impelled in the radial direction by impelling means. The tip end part of each of the vanes is slidably pressed against the outer circumferential surface of each of the rollers 16 and 17. Each of these vanes is configured in such a manner as to partition the cylinder chamber of each of the cylinders 13 and 14 into a suction chamber and compression chamber in cooperation with each of the rollers 16 and 17 and move (advance/retreat) in the direction of protrusion into the cylinder chamber and direction of retreat from the cylinder chamber concomitantly with the eccentric rotation of each of the rollers 16 and 17. Each of the vanes advances/retreats into/from the cylinder chamber as described above, whereby the capacity of each of the suction chamber and compression chamber of the cylinder chamber is changed, and vapor-phase refrigerant sucked into the cylinder chamber from the aforementioned suction pipe is compressed.

The high-temperature/high-pressure vapor-phase refrigerant compressed in each of the cylinder chambers of the first cylinder 13 and second cylinder 14 is discharged into the inside of the airtight container 10 through each of discharge valve mechanisms 21 and 23 to be described later. The discharged vapor-phase refrigerant ascends inside the airtight container 10. Furthermore, while the compression-mechanism unit 11 is in operation, the lubricating oil stored in the oil basin part 10 c of the airtight container 10 is stirred. The stirred lubricating oil is changed into a mist-like form and ascends inside the airtight container 10 toward the discharge pipe 10 b under the favor of the flow of the vapor-phase refrigerant. Inside the airtight container 10, an oil separator or the like configured to separate the lubricating oil contained in the vapor-phase refrigerant ascending inside the container 10 from the refrigerant is provided.

The electric-motor unit 12 is accommodated in the airtight container 10 at an intermediate part along the central axis line O1 of the airtight container 10 in such a manner as to be positioned between the compression-mechanism unit 11 and discharge pipe 10 b. The electric-motor unit 12 includes a so-called inner-rotor type motor and includes a rotor 33 firmly fixed to the rotating shaft 15 and stator 34 fixed to the inner circumferential surface of the circumferential wall 10 a of the airtight container 10. A voltage is applied to the electric-motor unit 12 from the power source, whereby the rotor 33 is rotated around the central axis line O1 relatively to the stator 34 and rotating shaft 15 is rotated together with the rotor 33. The rotating shaft 15 is rotatably supported by the two bearings 20 and 22.

One of the two bearings 20 and 22 is a main bearing (hereinafter referred to as a first bearing) 20 and the other is an auxiliary bearing (hereinafter referred to as a second bearing) 22. Each of the first bearing 20 and second bearing 22 rotatably supports the rotating shaft 15. Further, the first bearing 20 defines the top surface of the first cylinder chamber in the first cylinder 13 and second bearing 22 defines the undersurface of the second cylinder chamber in the second cylinder 14. The top surface is an end face of each of the cylinders 13 and 14 on one end side thereof in the axial direction (direction along the central axis line O1 of the airtight container 10) of the rotating shaft 15, and undersurface is an end face of each of the cylinders 13 and 14 on the other end side thereof in the aforementioned axial direction. In other words, the first bearing 20 corresponds to a member blocking the first cylinder chamber from above, and second bearing 22 corresponds to a member blocking the second cylinder chamber from below.

The first bearing 20 includes a first flange part 20 a defining the top surface of the first cylinder chamber in the first cylinder 13 and first boss part 20 b upwardly extending in a cylindrical form so as to be continuous with the first flange part 20 a.

The first flange part 20 a is positioned at the lower end of the first boss part 20 b, extends toward the outside of the first boss part 20 b in the radial direction thereof, and is continuous throughout the entire circumference of a circular shape concentric with the central axis of the rotating shaft 15. In the first flange part 20 a, a discharge hole (hereinafter referred to as a first discharge hole) 20 c (see FIG. 3 ) through which the refrigerant is discharged from the compression chamber of the first cylinder 13 is formed. The first discharge hole 20 c penetrates a part of the first flange part 20 a in the vertical direction and communicates with the inside of the compression chamber of the first cylinder 13. The first discharge hole 20 c is opened/closed by a predetermined valve mechanism (hereinafter referred to as a first discharge valve mechanism) 21. The first discharge valve mechanism 21 is arranged in the first flange part 20 a, opens the first discharge hole 20 c concomitantly with an increase in the pressure inside the compression chamber of the first cylinder 13 to thereby discharge the high-temperature/high-pressure vapor-phase refrigerant from the compression chamber.

The first boss part 20 b is a part into which the rotating shaft 15, more specifically, the first journal part 27 a is inserted at the first bearing 20, and which rotatably supports the first journal part 27 a. The first boss part 20 b is arranged so as to be concentric with the rotating shaft 15. That is, the first boss part 20 b is arranged perpendicular to the first flange part 20 a. In the state where the first journal part 27 a is inserted into the first boss part 20 b, the outer circumferential surface thereof is slid along the inner circumferential surface of the first boss part 20.

The second bearing 22 includes a second flange part 22 a defining the undersurface of the second cylinder chamber in the second cylinder 14 and second boss part 22 b downwardly extending in a cylindrical form so as to be continuous with the second flange part 22 a.

The second flange part 22 a is positioned at the upper end of the second boss part 22 b, extends toward the outside of the second boss part 22 b in the radial direction thereof, and is continuous throughout the entire circumference of a circular shape concentric with the central axis of the rotating shaft 15. In the second flange part 22 a, a discharge hole (illustration omitted, hereinafter referred to as a second discharge hole) through which the refrigerant is discharged from the compression chamber of the second cylinder 14 is formed. The second discharge hole penetrates a part of the second flange part 22 a in the vertical direction and communicates with the inside of the compression chamber of the second cylinder 14. The second discharge hole is opened/closed by a predetermined valve mechanism (hereinafter referred to as a second discharge valve mechanism) 23. The second discharge valve mechanism 23 opens the second discharge hole concomitantly with an increase in the pressure inside the compression chamber of the second cylinder 14 to thereby discharge the high-temperature/high-pressure vapor-phase refrigerant from the compression chamber.

The second boss part 22 b is a part into which the rotating shaft 15, more specifically, the second journal part 27 b is inserted at the second bearing 22, and which rotatably supports the second journal part 27 b. The second boss part 22 b is arranged so as to be concentric with the rotating shaft 15. That is, the second boss part 22 b is arranged perpendicular to the second flange part 22 a. In the state where the second journal part 27 b is inserted into the second boss part 22 b, the outer circumferential surface thereof is slid along the inner circumferential surface of the second boss part 22 b.

In each of FIG. 3 and FIG. 4 , the configuration of the first discharge valve mechanism 21 is shown. FIG. 3 is a view schematically showing the first bearing 20 including the first discharge valve mechanism 21 from above. FIG. 4 is a cross-sectional view schematically showing the first bearing 20 at the part indicated by the arrows A3 shown in FIG. 3 . The configurations of the first discharge valve mechanism 21 and second discharge valve mechanism 23 are approximately equal to each other except for the fact that there is a point of difference incidental to the fact that the mechanism 21 and mechanism 23 are positioned opposite to each other in the vertical direction. Accordingly, the configuration of the second discharge valve mechanism 23 conforms to the configuration shown in FIG. 3 and FIG. 4 . Accordingly, hereinafter the configuration example of the first discharge valve mechanism 21 will be described.

As shown in FIG. 3 and FIG. 4 , the first discharge valve mechanism 21 is provided in the first flange part 20 a of the first bearing 20, appropriately opens the first discharge hole 20 c to thereby discharge the refrigerant compressed in the compression chamber of the first cylinder 13 from the compression chamber. The first discharge valve mechanism 21 includes a discharge valve 21 a and valve presser 21 b. The discharge valve 21 a and valve presser 21 b are fixed to the first flange part 20 a with a predetermined fixing member 21 c. As the fixing member 21 c, an arbitrary fixing member, for example, a bolt, screw, rivet or the like is applied.

The first discharge hole 20 c is opened at the bottom of a concave part (hereinafter referred to as a dug-down part) 20 d formed in the first flange part 20 a. The dug-down part 20 d is formed by making the top surface (end face on one end side in the axial direction of the rotating shaft 15) of the first flange part 20 a concave to a predetermined depth. The depth of the dug-down part 20 d is made approximately equal to the dimension of the first discharge valve mechanism 21 (valve presser 21 b laid on top of discharge valve 21 a) in the vertical direction. The contour of the dug-down part 20 d viewed from above the first flange part 20 a is made a similar figure of the contour slightly greater than the aforementioned contour of the first discharge valve mechanism 21 viewed from above the first flange part 20 a so that the first discharge valve mechanism 21 (discharge valve 21 a and valve presser 21 b) can be installed inside the dug-down part 20 d. That is, the longitudinal direction of the dug-down part 20 d is parallel to the longitudinal direction of the discharge valve 21 a and valve presser 21 b to be described later. By making the dug-down part 20 d have such a configuration, when the first discharge valve mechanism 21 is installed inside the dug-down part 20 d, the mechanism 21 is in a state where the mechanism 21 is fully hidden in the dug-down part 20 d. In other words, the dug-down part 20 d is formed in the first flange part 20 a as a concave part in which the first discharge valve mechanism 21 is to be installed. It should be noted that in the second flange part 22 a of the second bearing 22, a dug-down part 22d (see FIG. 2 ) identical to the dug-down part 20 d is formed as a concave part in which the second discharge valve mechanism 23 is to be installed.

The discharge valve 21 a is a member configured to close or open the first discharge hole 20 c, and has a plate-like shape lengthwise in the predetermined direction. The discharge valve 21 a is formed of a material capable of elastic deformation such as spring steel or the like into an oblong card-like shape. Thereby, the discharge valve 21 a is made to have a cantilever leaf spring structure capable of flexure deformation in the state where one end thereof in the longitudinal direction fixed by a fixing member 21 c is made the fixed end, and the other end thereof in the longitudinal direction is made the free end. More specifically, when the high-temperature/high-pressure vapor-phase refrigerant compressed in the compression chamber of the first cylinder 13 reaches the predetermined discharge pressure, the discharge valve 21 a undergoes deformation and opens the first discharge hole 20 c. Hereinafter, this state of the discharge valve 21 a is referred to as the deformed state. In the state (hereinafter referred to as the normal state) before the first discharge hole 20 c is opened, the discharge valve 21 a is in pressure contact with the circumferential edge of the first discharge hole 20 c in such a manner as to block up the first discharge hole 20 c by an elastic force (pressing force) less than the aforementioned predetermined discharge pressure. Accordingly, when the refrigerant exceeds the ambient pressure inside the first muffler 41 to reach the predetermined discharge pressure, the discharge pressure deforms the discharge valve 21 a against the elastic force (pressing force) thereof to thereby make the discharge valve 21 a open the first discharge hole 20 c and discharge the refrigerant. When the first discharge hole 20 c is opened to discharge the refrigerant and discharge pressure of the refrigerant becomes lower than the predetermined pressure, the discharge valve 21 a is elastically restored from the deformed state to the normal state and blocks up the first discharge hole 20 c again.

The valve presser 21 b is a member configured to restrain the discharge valve 21 a from deformation, and has a plate-like shape lengthwise in the predetermined direction and having a thickness greater than the discharge valve 21 a. The valve presser 21 b is formed of, for example, a steel material or the like. The valve presser 21 b is arranged in such a manner that the longitudinal direction thereof is made along the longitudinal direction of the discharge valve 21 a. These longitudinal directions are directions intersecting the radial direction of the first flange part 20 a, in other words, the directions intersecting a plane including the central axis of the rotating shaft 15. Further, these longitudinal directions are parallel to the longitudinal direction of the dug-down part 20 d. In the example shown in FIG. 3 , the aforementioned longitudinal direction is the direction orthogonal to the radial direction of the first flange part 20 a, in other words, the direction orthogonal to the plane including the central axis of the rotating shaft 15. The valve presser 21 b is arranged in such a manner as to be opposed to the discharge valve 21 a in the process in which when opening the first discharge hole 20 c, the discharge valve 21 a makes a displacement to a position separate from the first discharge hole 20 c. In the example shown in FIG. 3 and FIG. 4 , the valve presser 21 b is arranged above the discharge valve 21 a in such a manner as to cover the discharge valve 21 a. The valve presser 21 b exhibits a bent (slightly levitated) state for opening the first discharge hole 20 c, i.e., a retroflex configuration conforming to the posture of the discharge valve 21 a in the deformed state. Thereby, when the discharge valve 21 a undergoes flexure deformation so as to open the first discharge hole 20 c, i.e., when the discharge valve 21 a enters the deformed state, the valve presser 21 b gets contact with the deformed discharge valve 21 a to thereby prevent the discharge valve 21 a from undergoing further deformation (levitation).

On the first bearing 20, a muffler (hereinafter referred to as a first muffler) 41 configured to cover the first bearing 20 is provided. The first muffler 41 suppresses pulsation and noise caused by, for example, the refrigerant to be discharged from the compression chamber of the first cylinder 13 into the inside of the airtight container 10. The first muffler 41 covers the first bearing 20 so as to surround the part between the first flange part 20 a and first boss part 20 b, and forms a first muffler chamber 43 between the first flange part 20 a and first boss part 20 b. The first muffler chamber 43 is a space into which the high-temperature/high-pressure refrigerant compressed in the compression chamber of the first cylinder 13 is discharge from the first discharge hole 20 c in the first place. The first muffler 41 includes communicating holes 41 a configured to make the inside and outside (space above and below the first muffler wall) of the first muffler 41 communicate with each other. The high-temperature/high-pressure vapor-phase refrigerant discharged into the first muffler chamber 43 through the first discharge hole 20 c is discharged into the inside of the airtight container 10 through the communicating holes 41 a.

As shown in FIG. 2 , under the second bearing 22, a muffler (hereinafter referred to as a second muffler) 42 configured to cover the second bearing 22 is provided. The second muffler 42 suppresses pulsation and noise caused by, for example, the refrigerant to be discharged from the compression chamber of the second cylinder 14 into the inside of the airtight container 10. The second muffler 42 covers the second bearing 22 so as to surround the part between the second flange part 22 a and second boss part 22 b, and forms a second muffler chamber 44 between the second flange part 22 a and second boss part 22 b. The second muffler chamber 44 is a space into which the high-temperature/high-pressure refrigerant compressed in the compression chamber of the second cylinder 14 is discharge from the second discharge hole in the first place. The second muffler chamber 44 communicates with the first muffler chamber 43 through a communicating hole provided in the compression-mechanism unit 11. The communicating hole penetrates each of the second flange part 22 a, second cylinder 14, partition plate 18, first cylinder 13, and first flange part 20 a and is opened to the second muffler chamber 44 and first muffler chamber 43. The high-temperature/high-pressure vapor-phase refrigerant discharged into the second muffler chamber 44 through the second discharge hole reaches the first muffler chamber 43 through the aforementioned communicating hole and is thereafter discharged into the inside of the airtight container 10 through the communicating holes 41 a.

In FIG. 5 and FIG. 6 , the configuration of the first muffler 41 according to this embodiment is shown. FIG. 5 is a view schematically showing, from above, the state where the first muffler 41 is mounted on the first bearing 20. FIG. 6 is a perspective view schematically showing the first muffler 41.

As shown in FIGS. 4 to 6 , the first muffler 41 is a three-dimensional component including an end face part 45, side face part 46, and brim part 47, and these three parts are formed so as to have a thin-walled structure. The end face part 45, side face part 46, and brim part 47 define the outer contour of the first muffler chamber 43. The end face part 45 is a face part of the first muffler 41 on one end side thereof in the axial direction (direction along the central axis line O1 of the airtight container 10) of the rotating shaft 15 and is a face part radially spreading relatively to the central axis of the rotating shaft 15. In the example shown in FIG. 5 and FIG. 6 , the end face part 45 corresponds to the top face part of the first muffler 41. The end face part 45 has an annular shape including a circular opening 45 a in which the first boss part 20 b of the first bearing 20 is to be inserted. The center of the opening 45 a is positioned on the central axis (central axis line O1 of the airtight container 10) of the rotating shaft 15. In other words, the first muffler 41 is arranged in such a manner that the opening 45 a is concentric with the rotating shaft 15. The bore diameter (distance across the opening) of the opening 45 a is made approximately equal to the dimension of the outer diameter of the first boss part 20 b at the insertion portion.

The end face part 45 includes five piece parts 45 b to 45 f radially extending relatively to the center of the opening 45 a. The five piece parts 45 b to 45 f are arranged at approximately regular intervals in the circumferential direction of the opening 45 a. The five piece parts 45 b to 45 f are, except for the part between the piece part 45 b and piece part 45 f, gently continuous with each other in such a manner that adjacent piece parts gradually become closer to the centerline (central axis line O1 of the airtight container 10) of the opening 45 a. Of the five piece parts, each of the four piece parts 45 c to 45 f includes a communicating hole 41 a formed therein. It should be noted that the number of the piece parts included in the end face part is not limited to five, and may less than or equal to four, or may be greater than or equal to six.

The side face part 46 joins the end face part 45 (specifically, five piece parts 45 b to 45 f) and brim part 47 to each other in a cylindrical form throughout the entire circumference in the circumferential direction of the opening 45 a, in other words, the central axis of the rotating shaft 15.

That is, the side face part 46 corresponds to the outer circumferential part of the first muffler 41. Regarding the side face part 46, the part on the upper side thereof continuous with the end face part 45 has a cylindrical shape thinner than the part on the lower side thereof continuous with the brim part 47. In other words, the side face part 46 is inclined in such a manner that the greater the distance from one side thereof continuous with the brim part 47 toward the other side thereof continuous with the end face part 45, the closer to the centerline (central axis line O1 of the airtight container 10) of the opening 45 a the side face part 46 becomes.

The brim part 47 is a face part of the first muffler 41 on the other end side thereof in the axial direction (direction along the central axis line O1 of the airtight container 10) of the rotating shaft 15, and is a face part spreading approximately in parallel with the end face part 45 in a circular form concentric with the central axis of the rotating shaft 15. In the example shown in FIG. 5 and FIG. 6 , the brim part 47 corresponds to the undersurface part of the first muffler 41, and is continuous with the side face part 46 at a part of the first muffler 41 on the lower end side thereof. The brim part 47 includes through-holes into which the bolts are to be inserted. The bolt is an example of a fixing member (in this embodiment, a second fixing member used to fix the first muffler 41) configured to fix the first muffler 41 to the first flange part 20 a. In the example shown in FIG. 5 and FIG. 6 , the brim part 47 includes five through-holes 47 a to 47 e. Into each of these through-holes 47 a to 47 e, one bolt is inserted and, in total five bolts 48 a to 48 e are inserted into these through-holes 47 a to 47 e. These through-holes 47 a to 47 e are arranged alongside at approximately regular intervals in the circumferential direction of the opening 45 a. When viewed from the axial direction of the rotating shaft 15, the five through-holes 47 a to 47 e are arranged in such a manner that the each of the through-holes 47 a to 47 e is positioned between piece parts 45 b to 45 f adjacent to each other at the end face part 45. In other words, the five through-holes 47 a to 47 e and five piece parts 45 b to 45 f are arranged in such a manner that the through-holes 47 a to 47 e and piece parts 45 b to 45 f are alternately positioned in the circumferential direction of the opening 45 a with approximately equal phase angle differences held between the alternately arranged through-holes 47 a to 47 e and piece parts 45 b to 45 f. It should be noted that the number of the through-holes possessed by the brim part is not limited to five, and may be less than or equal to four, or greater than or equal to six. For example, it is sufficient if the number of the through-holes included in the brim part is made equal to the number of the piece parts included in the end face part.

The through-holes 47 a to 47 e respectively communicate with the through-holes 20 f to 20 j formed in the first flange part 20 a of the first bearing 20. In the example shown in FIGS. 3 to 6 , the first through-hole 47 a communicates with the first through-hole 20 f. Into these through-holes 47 a and 20 f communicating with each other, the bolt 48 a is inserted. Likewise, the second through-hole 47 b communicates with the second through-hole 20 g. Into these through-holes 47 b and 20 g communicating with each other, the bolt 48 b is inserted. The third through-hole 47 c communicates with the third through-hole 20 h. Into these through-holes 47 c and 20 h communicating with each other, the bolt 48 c is inserted. The fourth through-hole 47 d communicates with the fourth through-hole 20 i. Into these through-holes 47 d and 20 i communicating with each other, the bolt 48 d is inserted. The fifth through-hole 47 e communicates with the fifth through-hole 20 j. Into these through-holes 47 e and 20 j communicating with each other, the bolt 48 e is inserted. These bolts 48 a to 48 e are each fastened to the first cylinder 13. Thereby, the first muffler 41 and first bearing 20 are implemented on the first cylinder 13. In other words, the brim part 47 is fixed to the first cylinder 13 through the first flange part 20 a of the first bearing 20 with the bolts 48 a to 48 e. That is, the bolts 48 a to 48 e fix the brim part 47 to the first cylinder 13 through the first flange part 20 a.

The first muffler 41 includes a concave part 49 formed by inwardly denting a part of the portion defining the outer contour of the first muffler chamber 43 to be formed by the first muffler 41 toward the inside of the first muffler chamber 43. Hereinafter, the configuration of the concave part 49 will be described with reference to FIGS. 4 to 6 .

The concave part 49 has a configuration formed by denting each of the end face part 45 and side face part 46 toward the inside of the first muffler chamber 43. When viewed from the first muffler chamber 43, the concave part 49 is a convex part protruding into the first muffler chamber 43 and corresponds to a rib of the first muffler 41. That is, the concave part 49 functions as a reinforcing part configured to suppress deformation of the first muffler 41. In the example shown in FIGS. 4 to 6 , the concave part 49 has the configuration formed by denting each of the portion between the piece part 45 b and piece part 45 f at the end face part 45 and portion connecting between the piece part 45 b, piece part 45 f, and brim part 47 at the side face part 46 toward the inside of the first muffler chamber 43.

When projected onto the top surface 20 e of the first flange part 20 a from the axial direction of the rotating shaft 15, the concave part 49 is arranged in such a manner as to intersect the longitudinal direction of the dug-down part 20 d and thereby overlap the dug-down part 20 d. That is, the concave part 49 is arranged in the vicinity of the dug-down part 20 d, in other words, in the vicinity of the discharge valve 21 a and valve presser 21 b.

The concave part 49 is configured to include four face parts 49 a to 49 d as the main face parts. The first face part 49 a and second face part 49 b are opposed to each other as a pair approximately in parallel with each other in the circumferential direction of the opening 45 a. Further, the first face part 49 a and second face part 49 b are parallel to a predetermined plane (virtual plane) including the central axis of the rotating shaft 15 and intersecting the longitudinal direction of the discharge valve 21 a.

In this embodiment, as one example, the first face part 49 a and second face part 49 b are parallel to the plane including the central axis of the rotating shaft 15 and orthogonal to the longitudinal direction of the discharge valve 21 a. From another point of view, when the concave part 49 is projected onto the top surface 20 e of the first flange part 20 a from the axial direction of the rotating shaft 15, the first face part 49 a and second face part 49 b are arranged in such a manner as to intersect the longitudinal direction of the dug-down part 20 d, i.e., in this case, as to intersect the longitudinal direction of the dug-down part 20 d at right angles and thereby overlap the dug-down part 20 d, i.e., the discharge valve 21 a and valve presser 21 b.

The third face part 49 c and fourth face part 49 d are face parts continuous with each other and connecting between the first face part 49 a and second face part 49 b. The first face part 49 a and second face part 49 b are continuous with each other through the third face part 49 c and fourth face part 49 d. The third face part 49 c rises approximately in parallel with the centerline (central axis line O1 of the airtight container 10) of the opening 45 a, and connects between the first face part 49 a and second face part 49 b at the upper part thereof. The fourth face part 49 d rises so as to be inclined toward the centerline (central axis line O1 of the airtight container 10) of the opening 45 a, and connects between the first face part 49 a and second face part 49 b at the lower part thereof. The fourth face part 49 d is inclined in such a manner that the closer to one side (in this case, upper side) thereof continuous with the third face part 49 c, the closer to the centerline (central axis line O1 of the airtight container 10) of the opening 45 a becomes the fourth face part 49 d. The third face part 49 c and fourth face part 49 d are perpendicularly continuous with the first face part 49 a and second face part 49 b.

The third face part 49 c includes a through-hole 49 e into which a bolt 50 is to be inserted. The bolt 50 is an example of a fixing member (in this embodiment, a first fixing member configured to fix the first muffler 41) configured to fix the first muffler 41, specifically, the side face part 46 to the first boss part 20 b. As shown in FIG. 5 , on the first boss part 20 b, a seating face part 20 k including a flat seating face capable of coming into contact with the third face part 49 c is provided. The bolt 50 is fastened to a bolt-hole 201 formed in the seating face part 20 k. Further, the first face part 49 a and second face part 49 b are in opposition to each other with a separation distance (clearance) for prevention of interference with the head 50 a of the bolt 50 held between the face parts 49 a and 49 b.

As described above, the first muffler 41 is fixed to the first cylinder 13 is fixed to the first bearing 20, i.e., to the first cylinder 13 through the first flange part 20 a with the bolts 48 a to 48 e, and is fixed to the first boss part 20 b with the bolt 50. The first flange part 20 a is arranged in such a manner as to outwardly extend in the radial direction of the rotating shaft 15, and first boss part 20 b is arranged concentric with the rotating shaft 15. That is, the first flange part 20 a and first boss part 20 b are arranged orthogonal to each other. Accordingly, it is possible to firmly fix the first muffler 41 to the first bearing 20 in two directions, i.e., in the radial direction and axial direction of the rotating shaft 15. Thereby, it is possible to enhance the stiffness of the first muffler 41 against, for example, the inclination of the first boss part 20 b at the time of rotation of the rotating shaft 15.

Further, the first muffler 41 includes the concave part 49 arranged in the vicinity of the dug-down part 20 d of the first flange part 20 a. As described above, the concave part 49 functions as a reinforcing part configured to suppress deformation of the first muffler 41. Accordingly, it is possible for the concave part 49, when the rotating shaft 15 is rotated, to bear the burden of the force attempting to make the dug-down part 20 d undergo elastic deformation so as to incline the first boss part 20 b toward, for example, the first flange part 20 a. Owing to this, it is possible to suppress the elastic deformation of the dug-down part 20 d, and suppress such a deformation as to incline the first boss part 20 b toward the first flange part 20 a. As a result, it becomes possible to reduce the noise caused by, for example, the bending vibration of the rotating shaft 15.

It should be noted that the second muffler 42 includes no part corresponding to the concave part 49 possessed by the aforementioned first muffler 41. This is due to the following reason. As shown in FIG. 2 , regarding the second boss part 22 b of the second bearing 22, the length of the rotating shaft 15 in the axial direction thereof is less than the first boss part 20 b of the first bearing 20. That is, such a deformation as to incline the second boss part 22 b toward the second flange part 22 a hardly occurs to the second boss part 22 b and, even when deformed, the second boss part 22 b is not so largely deformed as the first boss part 20 b. Accordingly, in this embodiment, the second muffler 42 has the configuration in which the part corresponding to the concave part 49 is omitted. That is, the second muffler 42 can be configured in the same manner as the first muffler 41 except for the differences incidental to the point that the second muffler 42 has no part corresponding to the concave part 49 and point that the second muffler 42 is positioned opposite (upside down) in the vertical direction to the first muffler 41. However, the second muffler 42 may have a concave part identical to the first muffler 41.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions. 

What is claimed is:
 1. A compressor comprising: cylinders which compress a refrigerant; a rotating shaft arranged inside the cylinders and including eccentric parts; bearings each of which includes a flange part defining a surface in the cylinder in an axial direction of the rotating shaft, and a boss part extending in a cylindrical form concentric with the rotating shaft so as to be continuous with the flange part and rotatably supporting the rotating shaft; at least one of discharge valve mechanisms which is arranged in the flange part and includes a discharge valve deformed to be opened when the refrigerant compressed by the cylinder reaches a predetermined discharge pressure and lengthwise in a predetermined direction, and a valve presser suppressing further deformation of the discharge valve when the discharge valve is opened; and at least one of mufflers which covers the bearing so as to surround a part between the flange part and the boss part and forms, between the flange part and the boss part, a muffler chamber into which the refrigerant compressed by the cylinder is discharged, wherein as to the mufflers, an outer contour of the muffler chamber is defined by each of an end face part which is a face part on one end side of the muffler in the axial direction of the rotating shaft, a brim part which is a face part on the other end side in the axial direction of the rotating shaft, and a side face part which joins the end face part and the brim part to each other in a cylindrical form throughout the entire circumference in the circumferential direction of the rotating shaft, and at least one of the mufflers includes a concave part formed by denting each of the end face part and the side face part toward the inside of the muffler chamber.
 2. The compressor of claim 1, wherein the flange part includes a dug-down part which is formed by making an end face of the flange part on one end side in the axial direction of the rotating shaft concave, and in which the discharge valve and the valve presser are installed, and when projected onto the flange part from the axial direction of the rotating shaft, the concave part is arranged in such a manner as to intersect the longitudinal direction of the discharge valve and overlap the dug-down part.
 3. The compressor of claim 2, wherein the concave part is configured to include a first face part, a second face part, a third face part, and a fourth face part, the first face part and the second face part are parallel to a predetermined virtual plane including the central axis of the rotating shaft and intersecting the longitudinal direction of the discharge valve, and the third face part and the fourth face part are continuous with each other, the third face part joins the first face part and the second face part to each other at a part on one side in the axial direction of the rotating shaft, and the fourth face part joins the first face part and the second face part to each other at a part on the other side in the axial direction of the rotating shaft.
 4. The compressor of claim 3, wherein the third face part includes a through-hole into which a first fixing member used to fix the muffler to the boss part is to be inserted, and the first face part and the second face part are opposed to each other with a separation distance for prevention of interference with the first fixing member held between the first face part and the second face part.
 5. The compressor of claim 1, wherein the brim part includes a plurality of through-holes into which second fixing members used to fix the brim part to the cylinder through the flange part are to be inserted.
 6. An air conditioner comprising: a compressor of claim 1; a condenser connected to the compressor; an expanding device connected to the condenser; and an evaporator connected to the expanding device. 